BGA和POP返修

BGA Rework has become synonymous for SMT Rework in general. Many u sers’ needs focus around BGA/CSP/Flip Chip, so information found here pr ovides a general background, applicable not only to array packages, but al so to the broader SMT Rework market. Large sphere arrays (BGA), and s mall fine pitch arrays (CSP) demand configurations that combine precise t hermal management and high resolution optics, to ensure a void-free rewo rk process and accurate alignment.

De-soldered BGA component BGA components on a large server board What are the Challenges?

One system for the complete rework cycle - from component removal to re-soldering?

Large arrays (20-65 mm) need large optical field of view, whereas sm aller fine pitch CSP's (0,8-20 mm) need high magnification (both require g ood resolution)

Solder removal of irregular shaped residual

Need to remove the BGA, but leave the neighboring devices undisturb ed?!

Want instant profiling?

Multilayer board sizes from USB stick (12x40 mm) to server board (5 00x465 mm)?

The Finetech Solution

Remove, Clean, Paste, Reball, Replace

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Soldering new Component Residual Solder Remova

Desoldering Componen Applying new Solder Paste Finetech provides a single platform that can perform the complete rework cycle:

Melt solder and remove the defective component with a special ized nozzle design

Residual solder removal using a contactless process - done in a single sweep, it produces safe, reproducible cleaning

Printing of solder paste on PCB, direct component printing or dispensi ng

Reball either a single defective ball or an entire array

Placement and reflow of new component ensuring accurate alignment Process Camera for In-situ Process Observation

View of process cam

It can be used for obervation of the reflow process or for taking pictures/ videos for documentation purposes.

Split Field Optics and Zoom Magnification

Split Field Optic

The Split Field Optics Video Imaging System enables diametrically opposite corners of a large component, and its corresponding pad area on the sub strate, to be viewed

Recommended Rework Equipment

ZX-2000C

ZX-X7

ZX-380

ZX-1800C

ZX-X6

Package on Package (PoP)

Package on Package (PoP)

Package on Package (PoP) is an IC-packaging technology with vertical com bined logic and memory components where two or more BGAs (Ball Grid Arrays) are stacked. Normally the discreet logic is located in the bottom with a memory device on top of it. Because of the high package density, these components are very important for the communication technology (h andset makers etc.).

Beside an intelligent combination of bottom and top heating providing prec ise thermal management, a special nozzle design is required to pick up th ose components during rework.

PoP component on a PCB

Principle of a flip chip PoP component

Cross section of a PoP component

What are the Challenges?

The principle rework process is similar to BGA rework, but because of the vertical assembling a special clamping solution is necessary. The particula r packaging implies the following specific problems:

High-count fine ball pitch (<0,65 mm)

Reflow simultaneously on the PCB

Applying a sufficient clamping force to lift the component out of liquid solder without lateral movement

Reworking different component heights

Avoid disturbance of neighbored components on densely populated boa rds

Amount of warpage for each package must be limited

Precise force control during stacking to avoid shifting of already placed package levels

The Finetech Solution

Remove, Clean, Replace

De-soldering a PoP component

Soldering a PoP component

Preheating the PCB

Desoldering the PoP component without affecting neighbored compone nts by using software controlled heating units and qualified tooling

Pick up the component with Finetech’s special vacuum activated tweez ers

Removing residual solder material contactless to avoid any stress to th e solder pads

Pick up, flux-dip and precise alignment of each package

In a final step, simultaneous reflow of all interconnections; packages a nd PCB

Special Nozzle Design for Quick and Safe Rework

Clamping nozzle with actuated tweezers in small clearance between PoP a nd small passives

Front view on nozzle tip

Specific nozzle with vacuum controlled tweezers for de-soldering and s oldering

Nozzle can be adapted easily to different component heights by turnin g one screw

Thin and specially shaped tweezers to clamp the component on every stack level

Tweezers distance easily adjustable for rework on densely populated P CBs even in clearance of 0.3 mm to adjacent components

Synchronic tweezers actuation is freely software programmable to avoi d any stress to non-molten solder joints

Recommended Rework Equipment

ZX-2000C

X-X7

ZX-380

ZX-1800C